In industrial production, it is often needed to make a variety of holes in workpieces. Drill bits are usually used for making holes of relatively small diameters, in which case it has to be considered how to position the drill bits in order to accurately determine the positions of the holes.
There are currently three typical drilling ways. One is the use of numerically controlled machine tools for drilling, by which drill bits are positioned. Another way is to position the drill bits by jigs which are specially designed and fabricated for different workpieces. A still another way is to make proofs and puncture a hole, to scribe a workpiece by a scribing tool to locate the center of circle of the hole, to punch a small dot at the center of circle, and to position a drill bit by the small dot.
Both ways involving numerically controlled machine tools, which are expensive, and jigs, which have complicated structures and are expensive for design and fabrication, are only adapted for mass production, but not for small scale production. The third way, though suitable for small scale production, is done manually, having low efficiency and high labor intensity.